Apparatus For Producing And Handling A Flowing Substance

ABSTRACT

A system ( 1 ) for producing a dough starter culture is provided which comprises a plurality of reservoirs ( 15 ) pre-loaded with a small amount (“mother level”) of a previously obtained starter culture. Into the reservoirs ( 15 ) are inoculated the other ingredients required for the preparation of starter culture and the contents are left to ferment for a specified period of time to produce the required starter culture, which is then discharged as required from each reservoir ( 15 ). A “mother level” portion is retained in the reservoirs and is used to produce a next batch of starter culture. The system ( 1 ) operates automatically and is programmable so that a first pre-set interval of time which is less then the fermentation time is allowed to elapse from the start of fermentation in a first reservoir ( 15 ) before the ingredients are delivered into a succeeding reservoir ( 15 ), and a second pre-set interval of time is allowed to elapse after the starter culture is discharged from the first reservoir ( 15 ) before a next batch of the ingredients is delivered into the first reservoir ( 15 ).

TECHNICAL FIELD

The present invention relates to a system for producing and handling aflowing substance and in particular to a system for producing andhandling a starter culture such as, for example, dough starter culture.

BACKGROUND ART

Starter culture is a very delicate substance comprising microorganismswhich process organic matter, to produce compounds useful in dairy,baking, brewing and many other industries. Performance of thesemicroorganisms, and therefore the quality of starter culture is highlydependent on temperature conditions of the environment in which thestarter culture is produced. Even slight fluctuations of thistemperature may affect the process and the characteristics of the finalproduct may differ from the required ones. Fermentation time is also avery important parameter and must be accurately controlled. In aproduction line environment, such as for example, a bakery line, it isdifficult to provide a large-scale starter culture management systemwithout the need for a large number of staff for such operations ascontrol and monitoring of the process, cleaning, etc. On the other hand,manual operations are prone to mistakes which put the production atrisk.

Similar problems exist in production of any flowing substance in acontrolled environment on a large scale.

The present invention seeks to alleviate the above disadvantages.

SUMMARY OF THE INVENTION

Accordingly, the invention provides a system for producing and handlinga flowing substance comprising

mixing vessel for mixing ingredients for use in subsequent preparationof a flowing substance;

a first manifold for transferring the mixed ingredients from the mixingvessel into one of a plurality of reservoirs where the mixed ingredientsare combined with an initiating culture;

a first regulating means for maintaining predetermined conditions ineach reservoir suitable to allow a fermentation process to occur whichresults in the production after a specified time of a starter culture asa flowing substance having predetermined properties from the initiatingculture and the mixed ingredients;

a second manifold for transferring the starter culture from eachreservoir to at least one receiving container; and

an electronic control means operable to control the system to providedelivery of mixed ingredients to each reservoir in a specified sequenceso that a first pre-set interval of time elapses from the start offermentation in a first or subsequent reservoir before the delivery ofthe mixed ingredients into a succeeding next reservoir, that intervalbeing less than the fermentation time of the starter culture in thepreceding reservoir.

Ideally, the electronic control means is operable to control the systemso as to effect discharge of a desired first portion of the starterculture from a reservoir whilst retaining a desired second portiontherein, said retained second portion comprising an initiating culturefor subsequent production in that reservoir of a further batch ofstarter culture upon introduction of a next load of the mixedingredients; and to allow a second pre-set delay interval to elapseafter the discharge before introducing the next load of the mixedingredients into the reservoir.

Such arrangement of the system ensures availability of adequate suppliesof starter culture of required quality during a specified period oftime, for example during a production run of a bakery line, such as afive-day production week. Any number of reservoirs greater than one maybe employed in such a system. For example, eight reservoirs have beenfound to suit a five-day production plan and a fermentation time oftwelve hours in each reservoir.

Conveniently, the system comprises a first measuring means at each ofthe reservoirs for measuring required quantities of the ingredientsdelivered into each reservoir; a second measuring means for measuringrequired quantities of the ingredients in the mixing vessel; and a thirdmeasuring means for measuring a quantity of the starter culturedelivered into the at least one receiving container.

Ideally, the system further comprises a second regulating means formaintaining the conditions of the ingredients being mixed in the mixingvessel and a third regulating means for maintaining the conditions ofthe starter culture in the at least one receiving reservoir.

The system preferably comprises a first propelling means fortransferring mixed ingredients into each reservoir via the firstmanifold and a second propelling means for transferring the starterculture produced in the reservoir into the receiving container via thesecond manifold.

Ideally, the first regulating means comprises a first temperatureregulating means for regulating processing temperature of the mixedingredients and initiating culture being processed in the reservoir; thesecond regulating means comprise a second temperature regulating meansfor regulating temperature of the ingredients being mixed in the mixingvessel; and the third regulating means comprise a third temperatureregulating means for regulating temperature of the starter culture inthe receiving reservoir.

A temperature measuring means is ideally provided at each of the mixingvessel, reservoirs and the at least one receiving vessel.

Preferably, the first and the second propelling mean comprise first andsecond pumps respectively.

Conveniently, the first temperature regulating means comprises heatingmeans and cooling means for regulating the temperature of the mixedingredients and initiating culture being processed in each reservoir.The heating means may comprise a heating station having a water tank forheating water and a pipework which delivers the heat from the water inthe tank to the reservoirs. The cooling means may comprise a coolingstation which supplies a coolant to the tank via a cooling manifold.

In a preferred arrangement, the receiving container comprises a dosingvessel having measuring means from which dosing vessels requiredquantities of starter culture are transferred to further downstreamprocessing steps. Such a dosing vessel may be located in an area remotefrom the reservoirs. However, a smaller tank may be located at eachreservoir for local discharge of the contents of each reservoir.

In one application, the ingredients being mixed in the mixing vesselcomprise at least one powdery ingredient and at least one liquidingredient such as, for example, flour and an aqueous mediumrespectively for subsequent production of a starter culture, and mostideally, a starter culture for making dough for subsequent baking. Theaqueous medium may comprise, for example, water or milk.

In a most preferred arrangement, the system comprises at least onestorage container for storage of the powdery ingredient, the storagecontainer being connected to the mixing vessel via a delivery means. Thedelivery means comprises a delivery manifold leading from the storagecontainer to the mixing vessel, and the system further comprises aliquid manifold for supplying a liquid ingredient into the mixingvessel.

Ideally, the powdery ingredient is initially delivered from the storagecontainer into an intermediate dosage container prior to its transferinto the mixing vessel. From the dosage container, the powderyingredient is preferably delivered into the mixing vessel via aweight-difference measurement (loss-in-weight) mechanism.

Ideally, the first measuring means comprise a plurality of firstweighing mechanisms each connected to one of the plurality ofreservoirs; the second measuring means comprise a second weighingmechanism connected to the mixing vessel; the third measuring meanscomprise a third weighing mechanism connected to the at least onereceiving vessel.

Advantageously, the system also includes a plurality of supply manifoldsfor delivering cleaning and rinsing fluids from a cleaning station to aplurality of locations in the system, and a plurality of returnmanifolds for collecting and returning said fluids from said pluralityof locations back to said cleaning station. The system preferablyincludes spray means for spraying said fluids over components of thesystem at said plurality of locations.

Ideally, the electronic control means comprise a programmable logiccontroller (PLC) suitably programmed to read input signals from any ofthe first, second and third weighing means and from the temperaturemeasuring means, to process the input signals and then send, ifrequired, relevant output signals to any of the delivery means, thefirst and second propelling means and the first, second and thirdtemperature regulating means to actuate said means in a manner whichensures:

provision of required quantities of ingredients in the mixing vessel;

maintenance of a pre-determined temperature of the ingredients beingmixed in the mixing vessel;

delivery of required quantities of mixed ingredients at required timesfrom the mixing vessel to the reservoir;

control of a pre-determined temperature of the mixed ingredients andinitiating culture being processed in the reservoir; and

provision of required processing time intervals, so as to obtain astarter culture having pre-determined properties.

The PLC is linked to a real time clock for use in conjunction with thePLC program.

Ideally, the PLC is programmable to actuate the cooling station in orderto lower the temperature of the starter culture in a reservoir to retardor stop further fermentation in the reservoir.

Ideally, the PLC is programmable to control the second propelling meansto discharge the starter culture produced in a reservoir, save for aportion of the starter culture which remains in the reservoir and isintended for a subsequent cycle of production of starter culture in thisreservoir, the remaining portion being sufficient to serve as initiatingculture for the subsequent cycle. A sensor means is provided connectedbetween the reservoir and the PLC for enabling the PLC to determine thequantity of starter culture in the reservoir and preventing the quantityfalling below a predetermined quantity on actuation of the secondpropelling means. This ensures that sufficient starter culture isretained in each reservoir to enable a desired amount of fresh cultureto be prepared in that reservoir within a predetermined time.

The PLC is pre-programmed with information specifying the requiredamount of starter culture to be produced during a production run of thesystem.

In another aspect, the invention provides a method for producing doughstarter culture in the above described system having a plurality ofreservoirs comprising the steps of providing a plurality or reservoirsand:

a) pre-loading culture reservoirs with a desired amount of initiatingculture maintained at an oppression temperature;

b) filling at least one first reservoir with a relevant amount ofaqueous medium/flour mix;

c) allowing the contents of the first reservoir to ferment at aspecified fermentation temperature for a pre-set fermentation timeinterval;

d) cooling the so obtained fermented starter culture in the firstreservoir to an oppression temperature to stop the fermentation process;

e) discharging a desired first portion of the starter culture from thefirst reservoir whilst retaining a desired second portion therein, saidretained second portion comprising an initiating culture for subsequentproduction in the first reservoir of a further batch of starter cultureupon introduction of a next load of aqueous medium/flour mix;

f) upon expiry of a first pre-set delay interval from the start offermentation in the first reservoir, filling a subsequent reservoir withthe relevant amount of aqueous medium/flour mix;

g) allowing a second pre-set delay interval to elapse after thedischarge before introducing the next load of aqueous medium/flour mixinto the first reservoir; and

h) repeating steps c) to f) in respect of the subsequent reservoir as ifit were the first reservoir.

Preferably, the above steps are carried out continuously during aproduction run of the system.

Ideally, in the end of the production run a portion of the starterculture obtained in the last-used reservoir is retained for use as aninitiating culture in a subsequent production run of the system. Thisportion of starter culture may be discharged locally into a smallertank, collected and kept at an oppression temperature pending a nextproduction run.

In a most preferred arrangement the number of reservoirs is eight, thefermentation time is preferably about twelve hours including filling andcooling time, the fermentation temperature is about 21° C. and theoppression temperature is about 16° C.

Ideally, the time allowed for discharging and using the produced starterculture from a reservoir, the first pre-set delay interval and thesecond preset delay interval are each about three hours.

DISCLOSURE OF PREFERRED EMBODIMENTS

The present invention will now hereinafter be described with referenceto the accompanying drawings which show, by way of example only, oneembodiment of a system for producing and handling starter culture inaccordance with the invention.

In the drawings:

FIG. 1 is a schematic plan view of a system according to the invention;

FIG. 2 is an enlarged portion of FIG. 1 showing a flour silo of thesystem;

FIG. 3 is an enlarged portion of FIG. 1 showing a receiving hopper forflour, a mixing unit and a cleaning station of the system;

FIG. 4 is an enlarged portion of FIG. 1 showing a fermentation tank ofthe system;

FIG. 5 is an enlarged portion of FIG. 1 showing another two fermentationtanks of the system and a portion of a manifold leading to furtherstages of handling of starter culture;

FIG. 6 is an enlarged portion of FIG. 1 showing two dosing stations ofthe system;

FIG. 7 is a flow chart illustrating stages of a starter cultureproduction cycle of two fermentation tanks of an eight-tank system and atime sequence between the production cycle;

FIG. 8 shows two tables showing a 24 hour schedule of production cyclesof eight fermentation tanks in an eight-tank system for two subsequentdays; and

FIG. 9 shows a flow chart of a production cycle of a tank and itsinteractions with a system control unit.

Referring to the drawings, the system for producing and handling starterculture according to the invention is generally indicated by referencenumeral 1 (see FIG. 1). The system 1 is most suitable for and will bedescribed in connection with producing and handling starter culture forsubsequent use in baking of bread, pastries etc. Of course, the systemof the invention is not limited for use only with such type of starterculture and, indeed, is suitable for or can be suitably adapted toproducing and handling any type of flowing substances which requiretime- and condition-controlled management.

The system 1 comprises a storage container or a silo 2 in which apowdery ingredient, being flour in the present case, is stored. Theflour is discharged from an outlet at the bottom of the silo 2 andreceived in a delivery manifold comprising a pneumatic conveyingpipework 4. The flour passes through a sifter 3 into a receiving hopper5 where a required quantity of flour for preparation of a batch ofstarter culture is accumulated. From the receiving hopper 5 the flour isdischarged into a loss-in-weight screw feeder 6 a (FIG. 3). A rotaryvalve 6 provides gradual feed of the flour from the hopper 5 to thescrew feeder 6 a. The screw feeder 6 a delivers the flour into a mixingvessel or mixing unit 7 in which the flour is blended with an aqueousmedium, for example plain water to form a uniform mix. The ratio betweenthe quantities of flour and water dispensed depends on the recipe andcan be, for example, 50% of water and 50% of flour. Water is maintainedat a constant temperature, for example 21° C. (70° F.), by blendingwater from a mains water manifold 9, a chilled water manifold 10 and awarm water manifold 11. The quantity of water delivered into the mixingunit 7 is controlled by a flow-meter 8.

After the mix of flour and water is blended in the mixing unit 7, themix is pumped by a pump 12 through a pipework 40 into a tank orreservoir 15. The tank 15 is selected from several such tanks employedin the system 1. The present system 1 has eight tanks 15 (although onlythree are shown), but of course any suitable number of tanks can beemployed. Each tank 15 is installed on a load cell (not shown) whichdetermines when the tank 15 is filled with the required quantity of themix so that a signal can be given to the pump 12 to stop feeding the mixinto the tank 15.

In the herein described system 1 a certain amount of pre-preparedstarter culture (initiating culture) is pre-loaded in the tanks 15 atthe beginning of a production cycle of the tank before the flour/watermix is pumped into the tanks 15. This amount of initiating (starter)culture must not be less than a minimum amount for a given amount offlour/water mix. This minimum amount of initiating culture is known as a“mother level”. The “mother level” of initiating culture depends on therecipe and can be, for example, 20% of an overall volume of an initialmixture of the “mother level” of initiating culture with the flour/watermix to be fermented in a tank 15. Thus, a tank 15 pre-loaded with 20% of“mother level” of initiating culture is filled with 80% of theflour/water mix to form the required overall quantity of the initialmixture to be fermented. Once the tank 15 is filled, the initial mixtureof the “mother level” of initiating culture and the flour/water mix isleft to ferment in the tank for a specified time according to therecipe, for example, twelve hours.

During the fermentation process, the temperature of the mixture in thetanks 15 is maintained at a constant predetermined level, which may befor example 21° C. (70° F.), at which the microorganisms of the “motherlevel” of starter culture become active and start to ferment theflour/water mix. This temperature of the contents of each tank 15 isbrought to and maintained at the same level by supplying passing heatedwater to the tanks 15 from a water heater 16 via a heated water manifold16 a. During the fermentation process, the mixture is transformed into astarter culture which should be of the same characteristics as theinitiating culture of the “mother level” in each tank 15.

In the herein described use of the system 1 for producing and handlingstarter culture, the starter culture resulting from the fermentationprocess needs to be cooled at the end of the fermentation process to anoppression temperature at which the microorganisms of the starterculture are inactive. Such temperature may be for example about 16° C.(60° F.) or less. A cooling station 17 is provided for lowering thetemperature of the starter culture in the tanks 15 to the oppressiontemperature. The station 17 supplies coolant to the tanks 15 via acoolant supply manifold 17 a.

The oppressed starter culture is discharged as required from each tank15 via a discharge pump 20. The discharge pump 20 transfers the starterculture via a starter manifold 21 to dosing stations 25. Divertingvalves 22 are provided in the manifold 21 for directing of the starterculture into a correct manifold of the system.

At each of the dosing stations 25 the starter culture is received in areceiving container, or a holding hopper 26. The holding hopper 26 isinstalled on a measuring means, such as a load cell (not shown) whichdetermines when a batch of preset quantity of starter culture isdelivered into the holding hopper 26 so that a signal can be given tothe respective pump 20 to stop feeding the starter culture into theholding hopper 26. The holding hopper 26 stores the starter cultureuntil the batch is required for further steps to be carried using thestarter culture. For example, when a dough mixing system of a productionline calls for ingredients for dough, the holding hopper 26 dischargesthe batch of starter culture via an outlet manifold 28 to a requiredlocation.

During a production run, the starter culture produced in the tanks 15 isnot completely discharged from the tanks. A “mother level” of thestarter culture is retained in each tank 15 for the next productioncycle in that tank. At the end of a production period (perhaps a week),some starter culture is cooled to 16° C. (60° F.) and placed into astorage container 29 for use at the beginning of the next productionweek as a “mother level” for the tanks 15.

An example of a weekly scheme of operation of the system 1 for producingand handling starter culture will now be described below with referenceto FIGS. 7 and 8. The scheme applies to an eight-tank system and can bealtered to adapt to a system with different number of fermentation tanks15. The fermentation time of twelve hours mentioned above for a singletank 15 is taken to include the time for filling the tank 15 withflour/water mixture and for cooling the contents of the tank 15 at theend of the fermentation process from 21° C. (70° F.) to 16° C. (60° F.).Of course, the system 1 is not limited to the scheme of operationdescribed below and any other suitable way of organising the sequence ofthe steps of its operation ensuring continuous supply of freshlyproduced starter culture is possible.

At the start of a production week, the starter culture held over fromthe production run of the preceding week is split to provide “motherlevels” in the eight tanks 15. If this quantity of starter culture isnot sufficient to provide the necessary “mother levels” for all thetanks 15, then the starter culture needs to be built up prior toplacement into the tanks 15 by adding a necessary amount of flour/watermix and fermenting for 12 hours in order to obtain an amount of thestarter culture sufficient to be split amongst the tanks 15.

Referring to FIG. 7, at 100 Tank 1 is held pre-loaded with a “motherlevel” of starter culture at the beginning of a production cycle. The“mother level” quantity of starter culture is held at 16° C. (60° F.).At Time Zero, Tank 1 starts to be filled with flour/water mix at 21° C.(70° F.) and should be filled within 1 hour. At 101, Tank 1 is filledand the fermentation process begins. Ten hours later, at 102, thestarter culture produced in Tank 1 during the fermentation process ofthe mixture of the “mother level” of starter culture with theflour/water mix is ready for use. At this stage the fermentation processis oppressed by cooling the starter culture to 16° C. (60° F.). Thecooling process should be completed within one hour. This batch ofstarter culture is used within three hours. A “mother level” of thestarter culture is retained in the tank 15 for the next production cycleof the tank 15. Upon expiry of the three hours for using the starterculture, another three hours elapses before introducing the next batchof flour/water mix into the tank 15 for the next production cycle. At104, Tank 1 is ready for the next production cycle.

At 200, three hours after the beginning of the production cycle of Tank1 i.e. from Time Zero, Tank 2, which is held pre-loaded with a “motherlevel” of starter culture, is filled with flour/water mix at 21° C. (70°F.) within one hour. Steps 201-204, which are the same as the steps101-104 for Tank 1 are then followed.

FIG. 8 shows 24 hour schedules for Day 1 and Day 2 of the productioncycles illustrated in FIG. 7 for eight tanks. A production cycle of eachsubsequent tank starts three hours after the beginning of the productioncycle of a previous tank. The production cycles which have not completedat the end of Day 1 will continue to run during Day 2 until completed.The number of tanks in operation can be selected to match therequirement for starter culture batches needed to keep the downstreambakery adaptably supplied.

At the end of the production week the starter culture may be usedentirely from all the tanks 15, except for one tank. The amount of thestarter culture in the tank should be sufficient to be split amongst theeight tanks 15 and used as a “mother level” in the tanks during theproduction run of the next week. Alternatively, the remaining startercan be built up later by adding a necessary amount of flour/water mix asdescribed above. The starter culture remaining from the production runmay be pumped into a storage container 29 and stored at 16° C. (60° F.)so that the tank can be cleaned.

The system is cleaned using the known Cleaning-in-Place (CIP)technology. A commercially available CIP station 30 comprises a watertank 31 and a diluted detergent tank 32. The system 1 is adapted to becompatible with a known CIP station, such as the CIP station 30. Waterand diluted detergent are mixed at the station and the mix is deliveredto the components of the system 1 to be cleaned via a CIP supplymanifold 33. After cleaning, the fluids are delivered back to the CIPstation 30 via a CIP return manifold 34. Different components of thesystem 1 can be cleaned at different times and the components notengaged in an on-going production run can be cleaned during thisproduction run. The manifolds 21 to the dosing stations 25 are cleanedonly after a production run is completed.

A pre-programmed cleaning cycle is performed by the CIP station 30 forcleaning the tanks 15. The fluids are delivered into the tanks thoughspray balls 35 located at top regions of the tanks 15. The spray balls35 of each tank 15 wash all parts of the interior of the tank. Thefluids are drained from the tanks 15 via the discharge pumps 20. Afterpassing through the discharge pumps 20 the fluids are directed by thediverting valves 22 into the return manifold 34 and are brought back tothe CIP station 30. The CIP system 30 also provides hot or cold rinsingwater to the tanks 15 in the above described manner. Air blow manifold36 is provided to air purge the components of the system 1. Pipeworks 4and 40 are also cleaned using a pre-programmed cleaning cycle by passingcleaning and rising fluids through the pipeworks and returning thesefluids back to the CIP system 30.

The quantity of starter culture required weekly for a production runvaries depending on the quantity of dough being produced for thisproduction run. In the present system 1, a weekly production plan ofdough governs the quantity of starter culture produced by the system 1.

The present system 1 is controlled using a programmable logic controller(PLC) which is suitably programmed to read input signals from varioussystem components such as sensors, flow-meters, valves, pumps, loadcells, etc., run control logic in respect of the input signals and thensend output signals to the system to actuate a relevant system componentand/or adjust relevant condition via a regulating device in order toensure relevant production output in accordance with pre-inputtedparameters of the production run. The PLC is linked to a real time clockfor use in conjunction with the PLC program for sending output signalsto the system at relevant times. One example of the interactions betweenthe system and the PLC is shown in FIG. 9.

The sensors include, for example, a temperature sensor for the watersupplied into the mixing unit 7, temperature sensors for measuring thetemperature of the contents of the tanks 15 and holding hoppers 26.Sensors on valves and pumps determine the conditions of the valve or thepump, e.g. on/off, open/shut etc. Flow-meter 8 determines the quantityof water delivered into the mixing unit 7. Measuring means such as loadcells (not shown) determine the quantity of material delivered into thetanks 15 and holding hoppers 26.

The regulating devices include, for example, flow-meters at watermanifolds 9, 10 and 11 which blend water from these three manifolds toachieve a desired water temperature of about 21° C. (70° F.) in thearrangement shown, heater 16 for maintaining the fermentationtemperature in the tanks 15, cooling station 17, valves, pumps, etc.

The PLC allows the system to operate automatically during a productionrun, which could be a single run extending over several days. Systemconditions are operator-monitored by the use of one or more screens. Onescreen shows tank conditions such as “disabled”, “await filling”,“scheduled”, “discharge”, “cooling”, “ferment”.

If a tank is “disabled” then it is not included in the system forstarter production. In the mode “await filling” the tank is being filledand is waiting for the fill cycle to complete within the allowed time of1 hour for this example. In the “scheduled” mode, the tank has beenscheduled for inclusion in the production system but has not yetreceived instructions for next use. In the “discharge” mode the tank isin use for discharge of the starter culture. In “cooling” mode the tank,which has gone through the fermentation time at the temperature of 21°C. (70° F.) is cooled to 16° C. (60° F.) to retard the fermentation. In“ferment” mode the tank is going through the fermentation process at 21°C. (70° F.). Also within this screen it is possible to view the quantityand temperature of the material in each tank and the fermentation timeelapsed.

A set of screens is also provided which allows changes to be made to thetimes and temperatures of the tanks by manual intervention into theautomatic run. This screen optionally has password protection and willnormally only be accessible to an authorised person. For example, thefermentation temperature may be manually changed from 21° C. (70° F.) to24° C. (75° F.).

A further screen or set of screens allow system parameters such as forexample agitator speeds to be viewed and/or altered. Flour system screenallows such parameters as, for example temperature and quantity of flourin the silo 2 to be viewed.

Another screen is provided for viewing and adjusting the ratio ofwater/flour mix in the mixing unit 7, although normally the settings aremade and never changed. Also it is possible to view the flow rates offlour and water.

A cleaning-in-place (CIP) control allows for the CIP system to beenabled or disabled.

Alarms screen shows any current and historic alarms that the system hasexperienced. It displays current alarms highlighted. Alarms may signalwhen motor overload occurs or when the temperature in tank 15 exceedsthe permitted temperature. The alarms are acknowledged and/or attendedto or by an operator depending on their severity.

The system also comprises a computer and specialised software to allowscheduling of starter production and graphic monitoring of the system.The computer does not in itself carry out any control function. Anoperator inputs a production schedule for finished products (e.g. bread)for a time period such as a week. The software already contains therecipes and calculates the amount of starter culture required and whenit is required during the production run. The production schedule whendownloaded to the PLC sets up particular quantities of starter culturethat the tanks must produce to have sufficient quantity of starterculture ready at the appropriate times.

It will of course, be understood that the invention is not limited tothe specific details described herein, which are given by way of exampleonly and that various modifications and alterations are possible withinthe scope of the invention as defined in the appended claims.

1. The system for producing and handling a flowing substance comprisinga mixing vessel for mixing ingredients for use in subsequent preparationof a flowing substance; a first manifold for transferring the mixedingredients from the mixing vessel into one of a plurality of reservoirswhere the mixed ingredients are combined with an initiating culture; afirst regulating means for maintaining predetermined conditions in eachreservoir suitable to allow a fermentation process to occur whichresults in the production after a specified time of a starter culture asa flowing substance having predetermined properties from the initiatingculture and the mixed ingredients; a second manifold for transferringthe starter culture from each reservoir to at least one receivingcontainer; and an electronic control means operable to control thesystem to provide delivery of mixed ingredients to each reservoir in aspecified sequence so that a first pre-set interval of time elapses fromthe start of fermentation in a first or subsequent reservoir before thedelivery of the mixed ingredients into a succeeding next reservoir, thatinterval being less than the fermentation time of the starter culture inthe preceding reservoir.
 2. The system as claimed in claim 1 in whichthe electronic control means is operable to control the system so as toeffect discharge of a desired first portion of the starter culture froma reservoir whilst retaining a desired second portion therein, saidretained second portion comprising an initiating culture for subsequentproduction in that reservoir of a further batch of starter culture uponintroduction of a next load of the mixed ingredients; and to allow asecond pre-set delay interval to elapse after the discharge beforeintroducing the next load of the mixed ingredients into the reservoir.3. The system as claimed in claim 1, in which the electronic controlmeans comprise a programmable logic controller (PLC).
 4. The system asclaimed in claim 3, in which the PLC is pre-programmed with informationspecifying the required amount of starter culture to be produced duringa production run of the system.
 5. The system as claimed in claim 1comprising a plurality of reservoirs.
 6. The system as claimed in claim2, comprising a first propelling means for transferring mixedingredients into each reservoir via the first manifold and a secondpropelling means for transferring the starter culture produced in thereservoir into the receiving container via the second manifold.
 7. Thesystem as claimed in claim 1 in which the ingredients being mixed in themixing vessel comprise at least one powdery ingredient and at least oneliquid ingredient.
 8. The system as claimed in claim 7 in which, thepowdery ingredient comprises flour and the liquid ingredient comprisesan aqueous medium.
 9. The system as claimed in claim 7, in which thesystem comprises at least one storage container for storage of thepowdery ingredient, the storage container being connected to the mixingvessel via a delivery means, the delivery means comprising a deliverymanifold leading from the storage container to the mixing vessel and thesystem further comprises a liquid manifold for supplying the liquidingredient into the mixing vessel.
 10. The system as claimed in claim 6in which the PLC is programmed to control the second propelling means todischarge the starter culture produced in a reservoir, save for aportion of the starter culture which remains in the reservoir and isretained for a subsequent cycle of production of starter culture in thisreservoir, the remaining portion being sufficient to serve as initiatingculture for the subsequent cycle and in which a sensor means is providedconnected between a reservoir and the PLC for enabling the PLC todetermine the quantity of starter culture in the reservoir andpreventing the quantity falling below a predetermined quantity onactuation of the second propelling means.
 11. A method for producing astarter culture using the system of claim 1 comprising the steps ofproviding a plurality of reservoirs and: a) pre-loading the reservoirswith a desired amount of initiating culture maintained at an oppressiontemperature; b) filling at least one first reservoir with a relevantamount of aqueous medium/flour mix; c) allowing the contents of thefirst reservoir to ferment at a specified fermentation temperature for apre-set fermentation time interval; d) cooling the so obtained fermentedstarter culture in the first reservoir to an oppression temperature tostop the fermentation process; e) discharging a desired first portion ofthe starter culture from the first reservoir whilst retaining a desiredsecond portion therein, said retained second portion comprising aninitiating culture for subsequent production in the first reservoir of afurther batch of starter culture upon introduction of a next load ofaqueous medium/flour mix; f) upon expiry of a first pre-set delayinterval from the start of fermentation in the first reservoir, fillinga subsequent reservoir with a relevant amount of aqueous medium/flourmix; g) allowing a second pre-set delay interval to elapse after thedischarge before introducing the next load of aqueous medium/flour mixinto the first reservoir; and h) repeating steps c) to f) in respect ofthe subsequent reservoir as if it were the first reservoir.
 12. A methodas claimed in claim 11 comprising the step of retaining at the end ofthe production run a portion of the starter culture obtained in thelast-used reservoir for use as an initiating culture in a subsequentproduction run of the system.
 13. A method as claimed in claim 12, inwhich the fermentation time is about twelve hours including filling andcooling time, the fermentation temperature is about 21° C. and theoppression temperature is about 16° C.
 14. A method as claimed in claim13, wherein the time allowed for discharging and using the producedstarter culture from a reservoir, the first pre-set delay interval andthe second preset delay interval are each about three hours.